Human lymphoblastoid interferon is being produced from mass cultures of Namalva cells and purified with a small Celltech MoAb affinity column. This purified interferon will be used to immunize BALB/c mice using a modification of the procedure of Staehelin et.al. (PNAS 78, 1848, 1981). In addition, in vitro immunizations will be attempted. Growing hybridomas will be screened by inhibition of interferon effects in a cytopathic assay and by the Celltech RIA. The aim of this project is to produce MoAb to be used by the FCRC Fermentation Program for large scale purification and assay of interferons for the BRMP.